The invention relates generally to trailer hitch guide devices, and more particularly to trailer hitch visual alignment guide devices which remotely emblematically represent the hitch coupling element and the trailer coupling element.
In coupling a towing vehicle, such as an automobile to a towed vehicle, such as a trailer, it is commonplace to utilize a a hitch having a hitch ball on the rear of the towing vehicle and a tongue having a socket on the front of the towed vehicle. To couple, the towing vehicle is backed up so as to place the hitch ball beneath the socket, after which the tongue is lowered such that the socket slides over and engages the hitch ball, therein coupling the towing vehicle to the towed vehicle.
Heretofore, the operation of coupling between the towing vehicle and the towed vehicle has proven difficult, especially if performed single-handedly, because in most cases both the hitch ball and the socket are not within the field of vision of the driver. A number of trailer hitch guides have been described in the literature which aid the driver to align the hitch ball with the socket of the towed vehicle. Tague U.S. Pat. No. 3,818,599 discloses a sighting device which consists of a pair of telescoping antenna, each capped with a sighting tip, where the sighting tips are plumb, respectfully, over the center of the socket and the center of the ball. The driver backs the vehicle up until the two sighting tips just touch one another. Voelkerding's U.S. Pat. No. 3,765,703 invention is very similar in concept to Tague's. Berry's U.S. Pat. No. 4,285,138 again is very similar, except that his device includes plumb lines as well as the antenna fitted with sighting tips. Campbell's U.S. Pat. No. 4,054,302 version of the trailer hitch guide antenna are electrically lightable. Other trailer hitch guide devices that employ sighting tips extended such that the sighting tips are plumb to the coupling elements, include Hamilton U.S. Pat. No. 2,984,011, Schlegel U.S. Pat. No. 3,720,000, White U.S. Pat. No. 3,889,384, Pauffer U.S. Pat. No. 4,169,610, and Bohnet U.S. Pat. No. 3,015,162. The sighting tips in these patents are usually spherical in shape.
The application of the prior art, in general, relies heavily on the driver being able to align the two sighting tips which are spherical. Billiards is a game, which also relies on the alignment of two spheres, and to the uninitiated player, this is not a simple task. This difficulty was recognized by Lehtisaari, and in his patent, U.S. Pat. No. 3,918,746, entitled "trailer and towing vehicle coupler guide" the spherical sighting tips are replaced with a V and a post shaped combination of sighting tips.
The act of aligning the towing vehicle with the towed vehicle can be described spatially in terms of movement along the X and Y axis within the horizontal plane defined by the ground. The X axis can be arbitrarily assigned to define leftward and rightward turning movement of the wheels, and the Y axis can arbitrarily be assigned to define the frontward-backward motion of the towing vehicle. The X axis, therefore, defines the side to side orientation of the alignment of the hitch ball with the socket, and the Y axis then would define the front to rear orientation of the alignment. The prior art teaches that front to rear alignment is obtained when the two sighting tips first contact as the towing vehicle approaches the towed vehicle. An improved guide device would be one where the guide does not require a collision between the sighting tips to determine their relative position. The prior art also teaches that the sighting elements of the guide device are positioned to the rear of the towing vehicle. For vehicles where this view is obscured, such as a station wagon filled with luggage or a loaded truck bed, the driver's point of reference would be lost, and the trailer hitch guide devices would be of little use. An improved trailer hitch guide device would be one where the driver would have a choice of aligning the hitch and the socket either using the sighting elements of the guide device positioned to the side of the towing vehicle, or positioned to the rear of the towing vehicle.